Two-Step Crystallization Kinetics in Colloidal Hard-Sphere Systems

Schöpe, Hans Joachim; Bryant, Gary; Megen, W. van

doi:10.1103/physrevlett.96.175701

Cited by 179 publications

(189 citation statements)

References 26 publications

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“…The best known example of such a system is given by colloidal models of hard spheres, whose crystallization behaviour has been studied extensively [2,8,10,13,[49][50][51][52]. For hard spheres, several observations have suggested that the presence of a metastable fluid-fluid demixing transition is not a necessary condition for a dense precursor-mediated crystallization process [14,16,[53][54][55][56][57][58]. The role of density fluctuations, and their priority over structural fluctuations are still subject to investigation, and for the moment the importance of both contributions cannot be ruled out [59].…”

Section: Two-step Nucleation and Precursorsmentioning

confidence: 99%

Nonclassical pathways of crystallization in colloidal systems

Russo

Tanaka

2016

MRS Bull.

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Colloidal systems offer the ideal conditions to study the nucleation process, both from an experimental viewpoint, due to their relative large size and long time-scales, and from a modeling point of view, due to the tunability of their interactions. Here we review some recent works that study the process of colloidal crystallization from a microscopic perspective. We focus in particular on non-classical pathways to nucleation where the appearance of the solid crystals involves fluctuations of two (or more) order parameters. We interpret the non-classical behavior as a decoupling of positional and orientational symmetry breaking. We then consider how the nucleation pathway determines which polymorph is selected upon nucleation from the melt. Moreover we show how the study of nucleation pathways not only sheds new light on the microscopic mechanism of nucleation, but also provides important information regarding its avoidance, thus suggesting a deep link between crystallization and vitrification.

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Section: Two-step Nucleation and Precursorsmentioning

confidence: 99%

Nonclassical pathways of crystallization in colloidal systems

Russo

Tanaka

2016

MRS Bull.

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“…The dynamical arrest in 3D is expected to be enhanced by this geometrical frustration, because the system has to rearrange its local density optimized structure to reach longrange order 1 . The local geometrical frustration scenario is 1 It is found in 3D hard sphere systems that this geometrical frustration alone is not sufficient to reach a glassy state as it cannot sufficiently suppress crystallization [11,12,13], and additionally polydispersity is needed [14]. different in 2D.…”

Section: Influence Of Dimensionality On Frustrationmentioning

confidence: 99%

Partial clustering prevents global crystallization in a binary 2D colloidal glass former

2009

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Abstract. A mixture of two types of super-paramagnetic colloidal particles with long range dipolar interaction is confined by gravity to the flat interface of a hanging water droplet. The particles are observed by video microscopy and the dipolar interaction strength is controlled via an external magnetic field. The system is a model system to study the glass transition in 2D, and it exhibits partial clustering of the small particles [1]. This clustering is strongly dependent on the relative concentration ξ of big and small particles. However, changing the interaction strength Γ reveals that the clustering does not depend on the interaction strength. The partial clustering scenario is quantified using Minkowski functionals and partial structure factors. Evidence that partial clustering prevents global crystallization is discussed.PACS. 82.70.Dd Colloids -64.70.P Glas transition of specific systems Influence of dimensionality on frustrationIt is well known that the macroscopic behavior of crystalizing systems sensitively depends on dimensionality, as demonstrated by two examples: In 2D an intermediate phase exists between fluid and crystal, the hexatic phase, where the system has no translational order while the orientational correlation is still long-range [2,3,4]. Such a two step melting scenario is not known in 3D. The Ising model for ferromagnetics shows a phase transition for 2D and 3D but not for 1D [5]. For amorphous systems, however, it was found in experiments [6], simulations [7], and theory [8] that the glass transition phenomenology is very similar in 2D and 3D systems, both in dynamics and structure [6,9]. A subtle difference, the local density optimization in 2D and 3D, is the following: in 3D the local density optimized structure of four spheres is obviously a tetrahedron. However, it is not possible to completely cover space in 3D with tetrahedra, because the angle between two planes of a tetrahedron is not a submultiple of 360• [10]. The density optimized state with long-range order is realized by the hexagonal closed packed structure or other variants of the fcc stacking with packing fraction φ = π/ √ 18 ≈ 74%. The dynamical arrest in 3D is expected to be enhanced by this geometrical frustration, because the system has to rearrange its local density optimized structure to reach longrange order 1 . The local geometrical frustration scenario is 1 It is found in 3D hard sphere systems that this geometrical frustration alone is not sufficient to reach a glassy state as it cannot sufficiently suppress crystallization [11,12,13], and additionally polydispersity is needed [14]. different in 2D. There, the local density optimized structure and densest long-range ordered structure are identical, namely hexagonal. For the glass transition in 2D it is therefore expected that an increase of complexity is necessary to reach dynamical arrest without crystallization: in simulations an isotropic one-component 2D system has been observed undergoing dynamical arrest for an inter-particle potential that exhibits t...

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“…Using scattering techniques as well as microscopy, the crystallization process and the competing glass transition have been studied in detail during the past decade (see e.g. [12][13][14][15][16]). …”

Section: Introductionmentioning

confidence: 99%

Crystallization in suspensions of hard spheres: a Monte Carlo and molecular dynamics simulation study

Schilling¹,

Dorosz²,

Schöpe³

et al. 2011

J. Phys.: Condens. Matter

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The crystallization of a metastable melt is one of the most important non-equilibrium phenomena in condensed matter physics, and hard sphere colloidal model systems have been used for several decades to investigate this process by experimental observation and computer simulation. Nevertheless, there is still an unexplained discrepancy between the simulation data and experimental nucleation rate densities. In this paper we examine the nucleation process in hard spheres using molecular dynamics and Monte Carlo simulation. We show that the crystallization process is mediated by precursors of low orientational bond-order and that our simulation data fairly match the experimental data sets.

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Two-Step Crystallization Kinetics in Colloidal Hard-Sphere Systems

Cited by 179 publications

References 26 publications

Nonclassical pathways of crystallization in colloidal systems

Nonclassical pathways of crystallization in colloidal systems

Partial clustering prevents global crystallization in a binary 2D colloidal glass former

Crystallization in suspensions of hard spheres: a Monte Carlo and molecular dynamics simulation study

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